The present invention relates to gas turbine engine design, and in particular, to a gas turbine engine having an offset driven output shaft.
Light general aviation aircraft typically employ engine driven propellers to provide forward thrust. Many of these aircraft have been designed to employ internal combustion piston engines, but there is a relatively recent trend toward retrofitting such aircraft with gas turbine engines. However, a seemingly simple obstacle has so far stifled a more universal replacement of piston engines with gas turbines, and the difficulty is purely a matter of space. Piston engines are typically xe2x80x9cshort and fatxe2x80x9d, whereas gas turbine engines tend to be relatively xe2x80x9clong and thinxe2x80x9d. Accordingly, most light aircraft designed to employ a piston engine simply do not have the space to readily accommodate a retrofitted gas turbine engine.
A somewhat unrelated matter which occupies turboprop designers is keeping the installation inlet and exhaust losses to a minimum. The rather large gearbox required to reduce the rotational output speed to drive the propeller poses an obstacle which must be negotiated by designers in getting inlet air to the engine and extracting exhaust gas therefrom. A gas path which is long and is not straight suffers significant pressure losses. Long air inlet paths also typically require increased anti-icing protection.
Accordingly, there is a general need for improvements in the design of gas turbine engines, and in particular, to an engine better adapted for retrofitting a piston-powered aircraft.
It is an object of the present invention to provide an improved gas turbine engine.
It is another object of the present invention to provide a gas turbine engine which is better adapted to retrofitting a piston-powered aircraft.
It is another object of the present invention to shorten and straighten the gas path of a turboprop or turboshaft engine.
Therefore, in accordance with the present invention, there is provided a gas turbine engine comprising a gas turbine engine, comprising a gas generator module having an turbine shaft for providing rotating output power, and a reduction gearbox module having a gearbox input shaft and a main output power shaft, wherein the gearbox input shaft is drivingly connected to an intermediate drive shaft, the intermediate drive shaft being drivingly connected to the turbine shaft, and wherein the intermediate drive shaft is disposed at an angle to the turbine shaft.
There is also provided, in accordance with the present invention, a gas turbine engine comprising a gas turbine engine, comprising a gas generator module, the gas generator module including a compressor portion, a combustor portion, and a turbine portion, and having an turbine shaft for providing rotating output power, and a reduction gearbox module adapted to drivingly connect the gas generator module to an output power shaft, the reduction gearbox module being disposed substantially laterally beside the gas generator module.
There is also provided, in accordance with the present invention, a gas turbine engine comprising a gas generator module having an turbine shaft for providing rotating output power, and a reduction gearbox module adapted to drivingly connect the gas generator module to an output shaft, wherein the reduction gearbox module is drivingly connected to the turbine shaft through a bevel gear on the turbine shaft.